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Re: runlevel policy

On Mon, Sep 19, 2005 at 01:45:19PM -0400, Joe Smith wrote:
> "Paul E Condon" <pecondon@mesanetworks.net> wrote in message 
> news:20050919153759.GC7804@big...
> >On Mon, Sep 19, 2005 at 11:11:55AM -0400, Ron Peterson wrote:
> >>On Mon, Sep 19, 2005 at 10:40:46AM -0400, Ron Peterson wrote:
> >>
> >>> Can anyone explain why Debian's runlevel policy seems to have strayed
> >>> so far from traditional System V?  Why is xdm/gdm/kdm etc. in runlevel
> >>> three, for example?
> >
> >Debian, as a distribution, really doesn't use runlevels 3-5, but it does
> >set them up in skeletal fashion as a convenience to a local sysadmin who
> >wants to use them for local purposes. Mostly what is there is just what
> >Debian puts in runlevel 2. It saves a bit if copying by the sysadmin. I
> >don't think it is governed by policy. The policy is that 3-5 are for
> >local use.

> Basically the debian point of view is that runlevels are the wrong solution 
> to the problem.

Perhaps the BSD's are better in this regard.  However, to date, Debian
remains a System V derivative.  I would rather see Debian chuck the
runlevel concept altogether than capriciously cripple it (out of spite,
perhaps.. :)

> If you need to be able to interactive decide what services and subsystems 
> start up automatically, then you should use a truely interactive booting 
> system.

At the moment, I'm not really interested in an interactive boot.  But I
do think it's a bit crazy that booting single mode attempts to start
network services and nfs.  That can be a crippling position to be in if
you have nfs problems...

> Part of the reason for the trditional system is that packages are qquite 
> hard to remove in RedHat-style systems. If a debian sysadmin does not what 
> a display manager (Funny name, as they are more like a login-manager) they 
> can just uninstall it.
> The vast majority of the time a 'traditional' system is booted into either 
> runlevel 5 or runlevel 3. So often in fact that making all debian runlevels 
> equivlent to that  makes good sense. Basically it makes life easier on the 
> end user. In the quite rare case that some of the services are unwanted the 
> services can be stopped by hand or 'init=/bin/bash' can be used. 

I usually have a banana for breakfast.  So the only breakfast food I
should have in the house is a banana.  If I don't want a banana, I
should make a special trip to the store, or scrounge around for a couple
of raisins.


The (hopefully) quite rare case you mention can be the case when you
have to troubleshoot an important production server.  In such a case,
doing an init=/bin/bash doesn't give you a lot to work with.  I'd rather
have init=init, unless I'm truly desperate.

Sure, once a machine is in production, you generally leave it alone.
But during development/testing/troubleshooting, it's convenient to be
able to easily forklift a number of services in or out of use.
Personally, I like something like:

1 - no networking
2 - networking, local filesystems only
3 - networking + nfs
4 - <twilightzone>
5 - networking + nfs + display manager

There may be other non-runlevel ways to do the same thing.  Point is,
Debian currently provides neither; it has to be done by hand.  Not
terribly difficult work, but of course that's all relative to how much
experience you have.  I don't agree that it makes sense to make all the
runlevels the same.  Whether runlevels are the best way to determine
boot options or not, they are currently the de-facto way it's done, and
making them different is useful.

I am certainly open to other better ways of accomplishing the same


Ron Peterson
Network & Systems Manager
Mount Holyoke College

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